The invention relates to a noise control device for tracks comprising sound absorbing slabs mounted at the rails of the track, the slabs being supported on the rails via elastic sections, the slabs arranged between the rails self-supportingly bridging the space between the rails. Furthermore, the invention relates to sound-absorbing slabs for such a noise control device.
In a noise control device of the above-mentioned type known from DE 36 02 313 A1, the slabs arranged between the rails of the track consist of three plies or layers supported on the rail base, on the rail web and on the lower side of the rail head via elastic sections. The upper layer consists of a passable woven steel wire whose rim is glued, welded or vulcanized into the section. The middle layer forms a sound absorption layer and consists of glass wool or rock wool. This sound absorption layer rests on the lower layer which is a perforated wall or grate and is supported in a recess of the section in the region of the rail base. According to a further embodiment, the slabs are also arranged on the rail outer side and upwardly angled at their ends so as to form a lateral noise control wall. Such slabs of mineral wool do provide sufficient silencing at high frequencies, yet at low frequencies their silencing is insufficient. Furthermore, this construction has the disadvantage that under higher and repeated loads, the passable perforated layer of woven steel wire may become detached from its anchoring in the sections so that the sound absorbing layer arranged therebelow may become damaged. Moreover, the dust penetrating the perforated layer may deposit on the upper side of the sound absorption layer and thus the silencing effect may increasingly deteriorate.
From NL-A-9400910 a noise control device for tracks is known, in which slabs made of wood fiber concrete are arranged between the rails of the track, which slabs rest on the sleepers of the track and laterally abut on the rails with elastic strips interposed. There is no self-supporting mounting of these slabs.